Flexible coupling



Jung 24, 1941.`

R. A. SMITH Erm.

MEUBLE coUPLING Original Filed Feb. 25, 1939" 2 Sheets-Sheet 1 WIWI Nllil BY I 3am k ATTORNEYS June 24, 1.941.I RA, SMITH TAL Re. 21,843

' FLEXIBLE COUPLING Original Filed Feb.A 25, 1959 2 Sheets-Sheet 2 ATTORNEY S STATESjATl-:NT OFFICE Jen Acontiamo,

" N. J.. ma .mm J.

'late of Elizabeth. N. J.. by 'assignee l Y, f e 'ascissa steamy zi. 194e, sam

A f i .Nm 258,440,'Febl'lllry 25, l193N Application vfor 1 i reisgenoten zz. 194e, serial 510.353.131

'nomma `(ci. sei-s) The invention re1ates` to animpro'vement inV flexible coupllngsfor shafts and more particu# larlyin flexible couplings of vthe gearQtype; lIn

the usual arrangement of ofuilexibl'e coupling' the torque is transmntted from one mounted on one -shaftconcentricaliy surrounded by and meshing with an internal gear mounted in or part of a casing'invwhich the external gearl is located. 'I'he turque of the external gear is transmitted by the internal gear tothe musing and in turn to a second internal gear which meshes with an external gear mounted Vou the to be turned, exceptvin. the construction known as a three bearing or shaft supporting type of cou- -'p1ing which isessentially one-half`of the usual type of coupling. When the shaft ends carrying the external gears are closely adjacent, the inf ternal gears are mountedvin the ends of acylindrical casing, frequently` made of two half sections bolted together, -whjich surrounds the two adjacent ends of vtheshaftsfand theexternal gears mounted on' or operatively connected with them. In those situations where the shaft-to be driven is located at a considerable spacing from the driving shaft, a third or'intermediate shaft v Y 5' `shaft to the other by means ofan'externai gear of two adjacent external gears cooperating withvtwo-internalr gears mounted in the same casing which may be of two or more sections bolted together, it being `understood that vthe features of the present invention are equallyapplicable to the arrangement in which the'two external gears are'spaced so far apart that they require the internal gears to be mount- 'edinseparatecasinga l The casings carrying the internal gears are so constructed that they not only surround the extemal gears but also substantially 'enclo them at the hub end by means of plate-like rings or closure members which may bev integral with or separable from lthe ends of fthe casing. lOne f purpose of this construction is to provide an en#A closed space forv containing lubricant, such as oil, which will cover or at least be applied between the cooperating external and internal gear teeth during the rotation of the flexible coupling.

v When the shafts and the fiexiblecouplinghare maybe interposed betweenV them. Theends of the intermediate shaftjmay b Prvided with external gears or internal gears and the adjacent ends of the driving andthe driven shafts provided with the cooperating gear members.` In other words, if external gears are carried' by the `ends of the intermediate shaft. then the internal gears are carried by the driving and driven shafts and vice versa. With this arrangement, each end of the intermediate shaft together with each Yadjacent end of the other shafts carries only one-half of the exible coupling unit, that is to say. lonly one external and one internal gear.v

Hence, the casing section in which each internal gear is mounted surrounds' only one external gear and the part of the shaft on which it is mounted.

But whether the two pairs of external-internal gears are located so closely together that the internal gears maybe mountedin a single casing, which may be of two or more sections i bolted together, or are located so'far apart that the internal gears are mounted in separate casing sections, the mode of operation of the flexible coupling and of the pairs of gears is substantially similar,- and the three bearing or shaft supporting type is essentially half of the coniplete coupling just described. Accordingly, for

` thesake of simplicity of description it will be assumed that the flexible coupling under considnot rotating the oil or other fluid lubricant settles Ainto the lower part of the enclosing casing structure, whether it encloses only one o'r both of the external gears. ',Whenstationary the in'- wardly extending plate-like rings at the hub ends of the casing prevent the lubricant from leak- 'ing out ofthe casing up to the level of the lower edge of the central holein the plate-like rings. When the coupling structure is rotating the lubricant is thrown bycentrifugal force so as substantially to lill the space between the cooperating external and internal gear teeth.

The inner diameter of the internal gears is so close to the root diameter of the external gears, differing therefrom only by the sum of the clearances, that in order to Asimplify the definition of the invention in the description and inthe claims, it is considered .desirable to use words meaning .in eect substantially the root diameter of the external gears rather than the inner diameter of the internal gears to identify this limit designation. l

Flexiblecouplings of the gear type have frequently heretofore been so constructed that the space within the casing and close to the inner periphery thereof between the pairs of external and internal gears has been of such diameter and proportion that a considerable percentage of the available lubricant occupies this space while the flexible coupling structure is rotating, whereas at that time the gearsV should be thoroughly supplied with lubricant and it isdesirable to direct over a long period of operation all the lubricant to the gears. Therefis thus present ingear-type ilexible couplings of usual construction a quantity of lubricant for the gear teeth which is not directed or guided to the gear teeth when the coupling is rotating, hence is not available for elciently submerging the cooperating gears to the last portion of the contained lubricant. When rotating a large part of the contained lubricant is undi' rected or misdirected, other than to the teeth needing it.

In the usual construction, if the cooperating external and internalgears are made smaller in diameter, this reduces the quantity of lubricant which may be contained in the casing when the structure is stationary, and it has been found that there will not be a desirably sulclent quanty of lubricantl to be applied to the contacting teeth 'faces of the gears when they are operating.

Various expedients have been resorted to in anI effort to rectify this defect, but thus far, so far as we are informed, without satisfactory results, such as we have evolved. Our coupling now to `be described, due to removable lubricant displacer rings guiding substantially all the oil to the gear teeth when rotating, can lbe much smaller in diameter; much lighter in weight, much less expensive to make for a given shaft size,` and thereby our invention is most essential for lower cost and still gives comparable coupling shaft.

- and power capacity.

In the accompanying drawings illustrating -the preferred form of the invention, Fig. 1 is a longitudinal vertical section through the improved flexible coupling for use in connecting shafts rotating on a "substantially horizontalaxis; Fig..2

is a detail section taken on the line 2--2 of Fig. 1;

vertical axis; Fig. 4 is a view similar to Fig. 1 of a modified form of the invention; Fig. 5 is a detail section taken on theline 5- 5 of Fig. 4; Fig. 6 is a view similar to the upper half of Fig. 1 and shows another modified form of the invention; and Fig. 'l is a fragmental longitudinal vertical section of a`third modified form of the invention.

This improved gear type of flexible coupling, as illustrated in the drawings, comprises the two cylindrical hub members 5 and 6 adapted to be mounted on the adjacent ends of the shafts to be connected. The hub end of whole hub 5, that is, the end of the whole hub`farthest from the end of the shaft on which it is mounted, is provided with Fig. 3 is a vertical section of the improved flexible coupling for shafts rotating on a substantially In order that the cooperating external and internal gears at each end of the coupling structure may be properly lubricated during theA rotaltion of the structure a supply of' fluid lubricant is inserted through the ducts i6, and when the coupling structure is stationary, lthe lubricant i supply can be filled in until it rises to the level indicated at 3U in Figs. 1 and 2, that is to say, slightly below the inner edge `3l of the plate-like rings formi'ng the closure members 22. Such space is known hereinafter as the stationary lubricant space. In the improved flexible coupling structure of the present invention the greater proportion .of the fluid lubricant is directed, when the cou'- pling is rotating, into the spaces between and around the cooperating teeth Q f the external and internalgears by means of a lubricant deflector or. lubricant displacer ring which, in the form of the invention shown in Fig. 1 is a cylindrical ring consisting of the two sections 33 and 3l, which may fit snugly but slldingly within the casing and between the inner edges 33 of the internal gears 25 and 26. As shown. the inner surfaces or internal diameters 38 of the sleeve sections 33,and 34 are separated from the external surfaces Il of the hubs'i andi by a cylindrical space indicated at 3l. When the coupling structure is stationary and the lubricant drains into the lower part of the space 31 and the adjacent regions around the teethv of the external and internal gears up to the level 30, termed as stated above, the stationary lubricant space, there is enough lubricant storedto amply submerge the cooperating gears when the coupling is rotating, and the lubricant within the casing is thrown by centrifugal action outwardly and around the teeth.

'Ihe internal teeth 25 and 26 on the casing sections I9 and 20 are somewhat longer axially than the external teeth 2 and lIII on the hubs 5 and 6, (and for the sake of clearness are shown exaggeratedly elongated) .so that there may be the an external gear 8; and similarly the hub end of the whole hub 6 is provided with an external gear I Il. Each hub mem-ber may be provided with a keyway l5 and an oil duct I6.

The cylindrical casing for carrying the internal gears cooperating with the external gears on the hubs may consist of the two sections I9 and 20- fastened together as a unit by the bolts 2|. The

hub end of each section of the internal gear casing is provided with an annular-dish-shaped closure member 22, and the inner end 23 of each closure member may project into a recess 24 in the hub end of the whole hub `'members 5 and 6. The closure members 22 may be inseparably connected with their respective internal-gear casing sections.

The outer end of the casing section I9 is provided with the internal gear 25 which surrounds and meshes with the external gear B on the hub 5, and the inner surface of the outer end of the casing section 20 is provided with the internal gear 26 which surrounds and meshes with the internal gear HI onthe hub 6.

desirable axial movement between the intermeshing teeth. The inner edges-of the internal teeth terminate at the positions indicated at 39 and the length of the sleeve sections 33 and' 3l of the lubricant displacer ring is such that they take up substantially the whole of the distance from the shoulder 39- on the casing section I9 to the shoulder 39 lonk the casing section 20 and thereby insure that the external gears -do not come closer together axially than that. in the case where the inner vhub ends quite far apart. As a result of this arrangement of parts, the teeth of the internal gears 25 and 26 may be freely cut without interfering with the adjacent portions of the casing sections!! and 20. The ends of the casing may be provided with the inseparable covers 22 andthe stationary lubricant space within the casing will besuch that suillclent lubricant will be contained therein to supply the necessary amount for the lubrication of the cooperating gear teeth because practically all of it is directed to the meshing gear teeth when rotating. It is to be i noted that we enable substantially all the lubricant to be used on the teeth make a smaller-and less expensive coupling possible, yet, when the coupling is to be taken apart the removal of they sleeve sections 33`and 3l of the lubricant displacer ring permits the hubs 5 and 6 to be slid off the ends ofthe shafts without requiring the closure members to be removed from the casing sections I3 and 20.

The form of the invention shown in Fig. 3 is essentially tlie same in principle as that shown provided for each adjacent shaft end. The hub` section Il is adapted to be mounted on the upper end of the lower shaft and the hub section 42 is adapted to be mounted on the lower endo! the upperV shaft. On the enlarged periphery of the lower hub member 4I is the external gear I3 and on the enlarged upper end of the upper hub member I2 is the external gear 44. These external gears cooperate with the internal gears l5 formed on the inner surfaces of the upper and lower ends of the casing 46, the two'sections of which are connected by the bolts 41. VThe lubricant I8 for the gears 43-45 is contained in the dish-shaped annular member 50 which is provided with an annular gasket 5i to prevent leakage outwardly. The lubricant 53 for lubricating the cooperating gears 44-45 is held when the coupling structure is stationary, by the diaphragm 5l. The Joint between the upper cooperating external and internal gears -I5 is closed by the dish-shaped annular member 55 A perforated plate 56 closes the upper end of the coupling structure.

The lubricant displacing or deflecting member 4 of this form of the invention, is indicated by the cylindrical sections 58 and 59 andthey occupy in f the structure the same relative position that the sleeve sections 33 and 34 occupy in the form of the invention shown in Fig. 1. It will be understood of course that thequantity of lubricant 4B contained in the cap member 50 must not only be sufficient to cover the cooperating gear teeth 43-45 but also usually to permita portion thereof to travel upwardly when rotating into the space 51 between the external surface of the hub Il and the internal surface of the sleeve section 5l.

In like manner the quantity of lubricant 53 must be sufficient to travel 'upwardly when rotating tween each of the rings 8U which are similar to but smaller in external diameter than the lubrithrough the space 60`between the outer surface of the hub member l2 and the inner surface oi gear teeth "-45.

The modified form of flexible coupling shown in Fig. 4 comprises a hub 52 adapted to be mounted on oneof a pair of shafts to be coupled, and provided with an external gearr B3 which is. surrounded by and meshes withl the internal gear 64 carried by the inner surface of the outer end of the casing section 65; and a hub 66 adapted to be mounted on the other shaft and provided with the external gear B8 surrounded -by and meshing with the internal gear 69 carried lby the inner surface of the outer end of the casing section 1I. The two casing sections are provided at their inner ends with the flanges 13 which are fastened together by thev bolts 1I. To the outer end of each casing section is secured an annular `dishshaped closure member 10 which closes the casing down to its corresponding hub end 12. Each hub is provided with a keyway 13 and an oil duct II.

AIn this form of the invention the ring lubricant displacer is integral with each hub. The ring lubricant displacer 15 is connected with the hub' l2 by a circular neck or web 11 and the ring lubricant displacer 18 is connected with the hub il by` a circular neck or webv 19. Between each ring lubricant displacer and the cylindrical portion I0 of each hub is a deep, axially extending circum` f the sleeve member 5B to cover the cooperating 1s are perforated at intervals with the holes al. The capacity of the grooves 82 andthe spaces 85 adjacent the gears is sufficient for lubricant enough and more to submerge the teeth when the ends 88 of the -hubs 62 and 66. The ring lubricant displacers 15 and 18 function like the ring lubricant displacers 33 and 34 and are removable axially of the casing sections.

The modified form of flexible coupling shown in Fig, 6 is the same in its principal features as the coupling shown in Fig. 4, and the same ele-V ments' thereof have the same reference numerals as in Fig. 4. The form of coupling shown in Fig.

6 differs from'the coupling shown in Fig. 4 principally in the feature that there is interposed becant dlsplacers of Fig. 4, a lubricant displacer consisting of a ring of yieldable oil-proof rubber Il vwhich is tightly mounted on each ring 9|), but is slightly smaller in external diam'eter than the internal diameter of the casing. The yieldable ring rubber lubricant displacers'sl function in the same manner as the lubricant displacers 15 and 18 of Fig. 4.

'I'he flexible cou-pling .shown in Fig. 7 embodies the-principal features of the flexible coupling arrangement shown in Fig. 1. The ring lubricant displacer 93 of Fig. 7 differs from the ring lubricant displacer 34 ofFig. l in that its inner end is .provided with a radially extending flange 94 which lies against the face of flange 95 of the casing section 85, so that when the two casing sections are bolted together the two sections of the ring lubricant displacer are bolted together and held firmly between them. It will be noted that in this form o f the invention also the outer end |00 of the section 93 of the lubricant displacer stantially closing the casing `down to the hubs outside the two pairs of gear teeth, and a removterminates substantially flush with the inner end 81 of the internal gear 98 so as to prevent the external gear 9.9 from travelling inwardly `beyond the outer end oi' the lubricant displacer.

Whatis claimed is:

1. In a exible coupling for p shafts, a hub mounted on each shaft, each hub .being provided with external gear teeth, a casing surrounding said hubs and provided with internal gear teeth corresponding to and meshing with the external gear teeth, means attached to the casing for 4subabie sleeve-form lining composed of a plurality of sections located within the casing and lling substantially all the spaceaxially between the two pairs'of gear teeth but not transmitting torque therebetween, the inner diameter of the sleeve being substantially equal to the root diameter of the external gears. defining at least in part, a stationary fluid-lubricant space, the greater portion of which is of smaller radius than the root radius of the external gear teeth, and serving to y guide. when the coupling is rotating, substantially all the lubricant to the intermeshing gear teeth. 2. In a flexible coupling for shafts. a driving member and a driven member adapted to trans mit torque, an external gear on at least one oi' said members, a casing surrounding the external gear and being provided with an internal gear meshing with the external gear so that torque is transmitted from one to the other, means permanently attached to the casing tor substantially I greater part or the radially outer surface oi which is out of contact with said casing, said' ring serving to direct substantially all the lubricant to the intermeshing gears when the coupling is rotating.

3. In a flexible coupling for shafts, a driving member and a driven member adapted to transmit torque, an external gear on at least one of said members, a casing surrounding the external gear and being provided with an internal gear meshing with the external 'gear so that torque is transmitted from one tothe other, said gears being axially nearly oi equal length except for one of said gears being axially longer than the other by normal, axial-movement clearance which is of smaller axial extent than the adjacent external gear teeth length, means attached to the casing for substantially dwing the casing to the gear carrying member outside the gears, a removable lubricant-displacing ring located within the casing, defining, at least in part, a stationary fluid-lubricant-containing space the greater part oiv which is radially within the ring, said ring, when the coupling is rotating, serving to direct almost all the lubricant to those areas of the intermeshing gears which are in contact, except that lubricant which is directed to said axial clearance, said ring also serving to prevent the external gear from approaching closer to the other member than the adjacent end of the ring.

4. In a flexible coupling for-shafts, a hub` mounted on each shaft, each hub being provided with external gear teeth, a casing surrounding said hubs and provided with internal gear teeth corresponding to and meshing with the external gear teeth, means for substantially closing the casing to the hubs outside the two pairs of gear teeth, and a removable sleeve-form lining located within the casing and iilling substantially all the' space axially between the two pairs of gear teeth,v

but not transmittingtorque therebetween. saidl sleeve being of greater axial extent than either said internal teeth or said external teeth, the in nel' diameter of the sleeve being substantially equal to the root diameter of the external gears.

the casing and positioned across denning, at least in part, a stationary fluid-lubricant space, a substantial portion of which is of smaller radius than the root radius of said external gear teeth, and servingto guide, when the coupling is rotating. substantially all the lubricant to the intermeshing gear teeth.

5. In a iiexible coupling for shafts, a hub mounted on each shaft, each hub being provided with external gear teeth; a casing surrounding said hubs and provided with internal gear teeth corresponding to and meshing with the external gear teeth, the axial movement clearance between 'anus Y the internal gears and the external gears being in each case smaller than the external gear teeth length, means for substantially closing the casing to the hubs outside the two pairs of gear teeth, and a removable sleeve-form lining located within the casing and filling substantially all the space axially between the two pairs of gear teeth but not transmitting torque therebetween, the inner diameter of the sleeve being substantially equal to the root diameter of the external gears, defining, at least in part, a stationary duid-lubricant space a substantial portion of which is of smaller radius than the root radius of the external -gear teeth, and serving to guide when the coupling is rotating substantially all the lubricant to thoseareas oi' said gears which are substantially in contact with each other.

6. In a flexible coupling for shafts, a hub mounted on each shaft. each hub being provided with external gear teeth, a casing surrounding said hubs and provided with internal gear teeth corresponding to and meshing with the external gear teeth, said casing comprising a plurality. of parts, and a' removable lubricant-displacing ring located within the casing and positioned to assist in centering said parts oi said casing with respect to each other so as to give said parts of said casing a common axis mounted on each shaft, each hub being provided with external gear teeth, a casing surrounding said hubs and provided with internal gear teeth corresponding to and meshing with the external gear teeth, said casing comprising two coaxial parts adapted to be juxtaposed endwise, and a removable lubricant-displacing ring located within the line oi contact of said coaxial parts.

8. In a ilexible coupling for shafts, a hub mounted on each shaft, each hub being provided with external gear teeth, a casing surrounding said hubs and provided with internal gear teeth corresponding to and meshing with the external gear teeth, said casing comprising two annuli, juxtaposed axially endwise, a removable lubricant-,displacing annulus having an outer diameter substantially equal to the inner diameter oi said two annuli and being positioned across the line of contact of said two annuli.

9. In a ilexlble coupling, for shafts, a hub mounted on each shaft, each hub being provided with external gear teeth, a casing surrounding said hubs and provided with internal gear teeth corresponding to and meshing with the external gear teeth, means permanently attached to the casing for substantially closing the casing down to the hubs outside the two pairs of gear teeth, and a removable sleeve-form lining composed of a plurality of sections located within and against said casing. said casing comprising a plurality of parts endwise juxtaposed, said lining sections being endwise disposed and having a radial line of contact axially removed from a radial line of contact oi'` said casing parts.

10. A gear type coupling comprising a pair 0i similar endwise-juxtaposed casing elements and an oil-displacing annulus within said casing for assisting in centering said elements with respect to each other to give said parts oi' said casing a overlying sub- 

